Gene Therapy with Enterovirus 3 C Protease: A Promising Strategy for Various Solid Tumors.

Current cancer gene therapies rely primarily on antitumor immunity, but the exploration of alternative mRNA cargoes for direct antitumor effects is crucial to expand cancer gene therapies. Here we show that lipid nanoparticles (LNPs) carrying mRNA encoding a viral 3 C protease can efficiently suppress tumors by selectively inducing tumor cell apoptosis. In various solid tumor models, intracranial injection of LNPs carrying mRNA encoding the 3 C protease (3C-LNPs) significantly inhibits tumor growth and prolongs survival in glioblastoma models. Similarly, subcutaneous injection reduces tumor volume and inhibits angiogenesis in a breast cancer model, while intravenous injection inhibits tumor growth and angiogenesis and prolongs survival in hepatocellular carcinoma models. Mass spectrometry and cleavage site prediction assays identify heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) as the main target degraded by the 3 C protease. This study suggests that viral protease mRNA could be a promising broad-spectrum antitumor therapeutic.